This is a non-production environment: light traffic, only used during business hours, and the SLA is relaxed. Yet it runs 2× m5.4xlarge on-demand, 24×7, plus an oversized database — around $1,500/mo for almost nothing.
Targets (loose): p99 ≤ 300 ms, 99.0% availability, standard durability, under $200/mo.
Levers: downsize the instance class, switch the running schedule so it turns off nights and weekends, use Spot (fine for throwaway dev capacity), right-size the database, and keep backups on.